That is fine
My goal is not to rattle my teeth or the trunk
I strive towards full sound which can be accomplished by properly engineered setup for the car from the factory (my BMW has 16 speakers that can rattle teeth and it is definitely not targeted towards kids but people who will pay more for quality sound) or try to do your best to get the best sound with the best you can put together for the specific chassis
I never listen loud music but I can't stand garbage audio setup where all you hear is the bass

I've never understood why they think that the folks in the surrounding cars want to hear the noise (music?) thumping from their cars? The arrogance of imposing that on me drives me insane.

A subwoofer does not necessarily equate to the sort of folks you are describing. As Kavadarci said, every high end vehicle has something similar to replicate true concert sound, ever listened to an orchestra kettle drum on a fine in-car system? How about the deep kick drum in a rock-a-billy track from Johnny Cash, or even Jay-Z banging the bass (but just loud enough for you and your passengers).

I have been looking into some of the bluetooth speaker options to mount in a fabricated central console that sits over the transmission tucked up under the dash, like later cars have as factory. I don't really want to add iPod connection to my Becker, and this will be removable and modern with no wiring (being bluetooth) and can even be removed for on the fly beach parties and picnics.

Just because you have a subwoofer in your trunk that can rattle the car and piss off other drivers dosent mean that it has to. I have had this sub in my car for over a year now and have it set at just the right amount of bass to bring out the fullness of the music but not where it is rattling and disturbing others. Every now and then when we are on a lonesome stretch of road and the mood is right we will turn it up and really enjoy the music with the scenery. DirectLA is correct, we listen to classical, Sinatra, Dave Brubeck, world music and a variety of others and it really is something to hear it close to the way it was recorded. BTW, rap is never played in the car!